Thermometer



w.` M. cHAcE Agg. 2, 1927. 1,637,805

THERMOMETER- vFiled Feb. 4, 1924 2 Sheets-Sheetv 1 INVENl TOR.

Aug. 2 1927. 1,637,805

w. M. cHAcE l THERMOMETER l Filed Feb. 4. 1924 2 Sheets-Sheet' 2 INVENTOR.

I BY ,//zm/wm Patented Aug. 2, 1927.

. g1,637,805 PATENT OFFICE?.

lvvILLrAivr `oI-Incn, or DETROIT, ivrromenn.

THERMOMETER.

`App1ication filed February This invention relates to thermometers and the object of the invention is to provide a thermometer adapted for a multiplicity of uses and which will accurately indicate temperature in degrees. j

Another ob'ect of the invention is to prov vide a thermometer in which the indicating dial may be positioned'at a-distance from the operating unit permitting the device to be use d for indicating temperatures of ovens, refrigerators, and other closed chambers in which the temperature reading may be more easily taken from the outside ofthe chamber.

lA further object of the invention is to provide a thermometer including a bi-nietallic thermostatic element adapted to rotate a dial, a stationary pointer being provided to indicate the correct temperature reading von the dial.

Another object of the invention is to provide a thermometer including a casing which may be attached'over an opening provided in the chamber with. which the thermometer is to be used, the opening providing a means for the passing of fluid into the casing to the thermostatic element.

These objects and the several novel features of the invention are hereinafter more fully described and claimed and the Lpreferred form of construction by which these objects are attained is shown in the accompanying drawings in Whichy Fig. 1 is an elevati-on of a cookingvoven equipped with y my therm ometer.

Fig. 2 is an enlarged elevation of the thermometer.

Fig. 3 is a section talen on line 3m?) of Fig. 2.

Fig. 4l Fig. 3.

Fig. 5vis a vieW of an alternative type of thermometer.

Fig. 6 is a sect-ion taken on line 6-6 of Fig. 5.

Fig. Fig. 6.

As shown more particularly in Fig. 3 the thermometer comprises a casingl which is adapted to be attached to the casingl 2 of an oven, refrigerator, liquid ltank or other closed chamber by means of the bolts 3 and the Wall 2 is provided with an opening 4 to allow air or other fluid to enter the casing .1.

is a section taken on line 1 -l of 7 is a section taken on line 7-*7 of r' The casing 1 is provided With a bearing 5 in 4, 1924. serial No. 690,524

which a shaft 6 is rotatably mounted and this shaft 6 is provid-ed with a slot 7 Within the casing. A' thermostatic element is pro.- vided comprising twoV strips 8 and 9, the strip 8 being formed of a'metal havingaa high co-eiiicient of expansion or contracf tion underi temperature changes andthe strip 9 is formed of a metal having`I .a lower co-e'llicient of expansion or contraction under temperature changes .and these vstrips of metal are secured togetherthroughout.their length as is the usualconstruction. fThis biijnetallic element is curled into the formy of a spiral as shown in Fig. 4 and one end thereof is secured in. the slot 'if' of the shaft 6 by the screw y10 and the other vend thereof is secured to a lng -11 in the casing 1 by the screws 12. A diallB is secured to the shaft 6 exteriorlyy of the casing by means' of a provided with temperature readings through about one quarter of its periphery Within the limits of the expansion. andV contraction of the bi-meta'llic element. Foruse incooking ovens the temperature readings may be lgraduated from 100.to 100 degrees or higher if desired anda bi-metallic element is-used which is particularly adapted to this range of temperature changes. For normal use as a thermometer the dial is graduated for normal atmospheric temperature changes, and a bi-meta'llic element particularly adapted for this temperature range is utilized. It can thus be seen that by using different thermostatic elements and corresponding dials that this type of thermometer may be manufacturedfor any definite temperature range. A pointer 15 is secured to the'casing 1 by the screws 16 and indicates by means of the dial the temperature Within the casing 1.

In operation as the temperatureA rises in the casing 1 the bi-metallicl element 8 expands thus expanding the therinostatic element and turning the shaft 6 and dial 13 in a counter-clockwise direction to position the in Figs. 5, 6 and 7in which the shaft 6 is provided with a small gear 17 secured thereto 19 about a quarter of a turn during a change i of temperatures 'from one extreme to the which meshes with a larger gear 18 on a shaft 19 which is rotatably mounted inthe casing 1.A A` bi-metallic therinostatic element 2() is secured at one end in a slot provided in the shaft 19 and is secured at the opposite end to a lug 21 provided on theinterior of the casing 1. In the type. shown in Figs. Q, 3 and 4 the thermostatic element will turn the `shaft 6 and dial 13 about a quarter ot' a turn during a change of temperature from one eX- treme to the other and the thermostatic element 2() shown in Fig. 7 ivill turn the shaft other but by inea-ns of the gear 18 which is in alfour toone ratio with the gear 17 the shaft 6 may be given a complete.revolutionthus turning` the dial 22 through a complete revolution.` Forthis reason the dial 22 may be vgraduated `through its entire. periphery thus giving' a more accurate reading' of the temperatures.

Theyshafts 6 and 19 are rotatable in the bearings and it is to be understood that these shafts should be held iii'oinany material longitudinal movement. The shaft-190i Fig. 6 will naturally remain in its position in the bearing due to the connection of the thermo- Vstatic element thereto and the shaft 6 and the bearing member for the shaft 6 should be of such length as to prevent moving the gears out of mesh. In Fig. 3 the shaft 6 is held from `mate-rial longitudinal ymovement by reason of attachment of the bimetallic element at the inner end the dial at the outer end. Y i Y From the foregoing description it becomes evident that the device is very simple and efcient in operation, will not easily get out of order, that the dial may be accurately set by means of the screw 14 to give exact tempera `ture readings and provides a device which accomplishes the objects described.

Having thus fully described my invention, Y

its utility `and Inode of operation, What I claim and desireto secure by Lett-ersPatent of the United States is` i i .1

A thermometer for use with receptacles or chambers comprising the combination with the chamber wall having an opening therein,

of a cup shaped casing 'of metal open on one side and provided thereon with alperi'pheral flange, the opposite side being closed, means for attachingr the casing to the exterior ofthe chamber Wall covering the said opening, vthe closed end of the said casing having` a central. aperture, a shaft rotatably mounted therein and projecting on opposite sides `of the said end of the casing, a bimetallicelement on the inner end of the said shaft adapted by expansion and contraction to turn the saine, a Wheel on thefouter endl of the shaft haing gradnations arranged about therperiphery thereof, and ajstationary pointer vmember secured to the casing fand having an end portion lying contiguous to the periphery of the Wheel.Y

In testimony whereof, I sign this specification. i* l i WILLIAM l 

